Modern Engineering Thermodynamics

90 CHAPTER 3: Thermodynamic Properties
Table 3.11 Glossary of Technical Terms Introduced in Chapter 3
Isobaric process
Isochoric process
Internal energy
Enthalpy
Constant volume specific heat (c v )
Constant pressure specific heat (c p )
Allotropic
Triple point
Vaporization
Condensation
Melting
Solidification
Sublimation
Saturation
Critical state
Gas
Quality
Moisture
Wet vapor
Phase
Constant pressure process
Constant volume process
Total energy minus kinetic and potential energy
Internal energy plus the product of pressure and volume
The variation in specific internal energy with respect to temperature while holding
volume constant
The variation in specific enthalpy with respect to temperature while holding
pressure constant
Different solid forms of the same substance
The point where the solid, liquid, and vapor phases coexist in thermal equilibrium.
The transformation of a liquid into a vapor
The transformation of a vapor into a liquid or a solid
The transformation of a solid into a liquid (synonymous with fusion)
The transformation of a liquid into a solid (synonymous with freezing)
The transformation of a solid into a vapor
A condition that exists when two or more phases coexist in equilibrium
The peak of the vaporization curve
The state of any substance whose temperature is greater than that at the critical state
The ratio of the mass of vapor present to the total mass present
The ratio of the mass of liquid present to the total mass present (1.0 minus the quality)
A substance whose state is under the saturation dome
The physical state (or molecular configuration) of matter
SUMMARY
In this chapter, three of the five main techniques used in obtaining values for thermodynamic properties are discussed.
Equations of state, thermodynamic tables, and thermodynamic charts are valuable tools needed in the
thermodynamic analyses that occur in the following chapters.
This chapter also introduces many new technical thermodynamic terms, most of which are listed in the glossary
in Table 3.11. The reader is urged to learn the definitions of these terms. They are freely used in the remaining
chapters under the assumption that their meaning is fully understood by the reader.
Here are some of the more important equations introduced in this chapter. Be careful not to try to use them
blindly without understanding their limitations.
1. General property relations, Eq. (3.2):
and Eq. (3.3):
∂x
=
∂y
z
∂x
∂y
z
∂y
∂z
∂y
∂x
x
z
∂z
∂x
y
−1
= −1
2. The definitions of two new physical properties, Eqs. (3.5) and (3.6)
β = 1
∂v
= isobaric coefficient of volume expansion
v ∂T p
and
κ = − 1 v
∂v
∂p
T
= isothermal coefficient of compressibility
3. The definitions of the total and specific energy of a system from Eqs. (3.9) and (3.12):
E = U + mV 2
2g c
+ mgZ
g c